Ammonia absorption refrigeration method and apparatus



Feb. 24, 1925.

J. BUCHEL AMMONIA ABSORPTION REFRIGERATION METHOD AND APPARATUS FiledOct. 10, 1921 3 SheetsSheet 1 Feb. 24, 1%25. 1,527,833 J. BUCHEL AMMONIA"ABSORPTION REFRIGERATION METHOD AND APPARATUS Filed OcnclO, 1921 5Sheets-Sheet 2 MN... 7 min.

5565; 2w 1 9 A? 2 Me Feb. 24, 1925. 152?,833

.4. BUCHEL AMMONIA ABSORPTION REFRIGERATION METHOD AND APPARATUS Filed0ct. l0, 1 1 3 Sheets-Sheet I l ,1 j I 7 r a??? 7Z/65 do 6 Patented Feb;24, 192s.

TES

UNITED STA PATIENT OFFICE.

JULEB BUCHEL, OF NEW ORLEANS, LOUISIANA.

AM MONIA ABSORPTION REFRIGERATION METHOO AND APPARATUS.

- Application filed October 10, 1921. Serial No. 506,710.

ammonia gas 1s continuously boiled oil, re-- absorbed, and returned. tothe generator without the use of force pumps or other meehanical means.

My invention provides a refrigerating'sya tem which only requiresrtheapplication of heat and cooling water from any convenient source, therefrigeration once initiated being maintained continuously, and includesa number of specific features of construction and operation which willbecome clear from the following description taken in conjunc- 'tion'withthe -accom anying drawings forming part of this specification and inwhich Figure 1 is a diagrammatic View of my improved refrigeratingsystem;

Figure 2 is a fragmentaiy vertical central sectional view taken throughthe left hand re enerator and its connected valves;

igure 3' is a fragmentary central sectional View of the generatorshowing the arrangement of the evaporating pans therein; Figure his avertical central sectional view of the expansion valve; I

Figures 5 and 6 are horizontal sectional views on the lines 55 and 6-6,respectively, of Figure 3; and

Figure 7 1s a plan view of a valve part shown in Figure 2.

Drawing a vertical line through the axis of the generator as the centerof the system, the right and left sides are duplicates of each otherexcept vfor the condensing coil 5, the ex ansion valve 6, and'therefrigerating coil Similar parts of the nated with the same numeralusing the index a for the right side and the index b for the left side.

two sides are desig- Figure 1. A generator 1, filled'with aqua ammoniato line 54, kept continuously boiling by a source of heat 2,controlledby a valve 3, accumulates a pressure which is indicated bygauge 8 on dome 4;] The ammonia gas flows through pipe 9 into thedouble-pipe condenser 5, reaches valve 6 in a liquid state, forcesthisvalve open, flows into refri eratingcoil 7, vaporizes therein, passesout tll flows alternately into regenera'tors 11 and 11 through checkvalves 21 and 21 Ammonia gas also flows 'altern'atel'y' and rough pipe10, fills pipes'3l and 31",

intermittently from, domed through pipes v 17 and 17", valves 13 and13", pipes 18 and 18 to opposite sides through 12?- and 12" into thetops of regenerators 11 and 11".

Hot Weak liquor flows alternately and intcrmittently from generator 1through pipes 28 and 28?. If initiated through 28 it flows to the'top ofheating coil 2-7" inside of regenerator 11, down through; said coil,

emerges via 26, enters coil 25 of the intercooler 24", flowing down andout througl-i 29, then up and through filtering chamber 86", controlvalve 16 and connection 12", into the top of regenerator 11 to meet and;ab-

sorb ammonia gas entering via 21". -The regenerator 11 is at this timefull of ammonia gas under generator pressure.

Cooling water is supplied through valve 32, pipe 33, annular space 34 inthe double pipe condenser 5, pipe 35, to alternatinglv acting watercontrol valves 15,and 15. If a the flow is initiated through valve 15 itwill be conveyed through pipe 19 to the top of the cooling coil 30*,down through said coil, emerges via pipe 36, crosses to the right,enters the bottom of inter-cooler shell 24, flows upward therein, goesto waste through 37, carrying withit heat abstracted from condensationin 5, absorption in 11", and

hot liquor flowing through coil 25*.

' When regenerator 11 is under generator pressure valve 13 is closed andadmits no ammonia the top 0 11", water control valve 15" is gas andpressure via pipe 18 to a";

to cooling coil 3min regenerator 11 to ab stract the heatof'ab'so'rption, check valve a 21is closed, liquor control valve 16 iswide open but admits no liquor to 11 because of the balanced pressureand the hydrostatic head between 12 and the liquor level 54 below. a-

At this time regenerator 11" is under a .low pressure and absorbingammonia gas flowing in through check valve 21"; valve 13 is open andadmitting ammonia gas via pipe 18 to. the top of1l, water control valveis closed and does not admit any water via pipe 19 to cooling coil 3 in.11, liquor control valve 16 is admlttin 'cold 7 weak liquor to 11" indirect proportion to the amount of ammonia gas to be absorbed andmaintams a constant pressure and temperature in the refrigerating coilv7.

Whenever valve 16" admits. cold weak liquor to regenerator 11 an equalamount of hot weak li uor flows from28 down through heating coi 27 inregenerator 11 and prevents condensation of ammonia gas therein.

b However, when 11 is full of-str'ong liquor the heating coil 27generally supplies enough heatto cause the top surface of the containedliquor to boil, exceed the generator ressure, and force the contentsout'via chec valve 23 and nozzle 41 intothe upper pan 37 inside of thegenerator'l. This excess pressure also forces, some ammonia gas via'pipe 18? through the open equalizing valve 13 and pipe '17" into dome 4.However, when the system is operating muchbelow its full capacity the.coil 27 does not supply enough heat, owing toradiation and conductionlosses, to bring the top surface of the strong liquor in 11 to itsboiling temperature under generator pressure and 'there is then areverse flow of ammonia gas fro'Indome 4, via the open valve'13 and pipe18 into 11, causing the. liquorto flow.

ack into the generator'by gravity through check valve 23.

Generator 1 is provided with a vertical seriesof pans 37, 46 and .52 toreceive the strong liquor from nozzles 41" and 41 which flows downthrough the generator step by step. Every other pan in the series has acentralopenmg -38 and at the outer edges ofthe alternate pans annulargpenings 47,

so that the-liquor flows down in a zigzag path 7 and the ammonia gasupward in the same manner.

Both regenerators consist-ofa-shell 11,

heating coil 27, coolin coil 30,;standpipe 20- with horizontal branc essuch as 22 connect ing with check valves 21 and-23.- 7 Across the "top,a double T fitfiH gVVithI branches '12, 14 and 71 has tubular openings-55, 561and 57,

connecting the interior of vregenerators ll with the under side; ofdiaphragm: 60, "-93 and 72, respectively of theeonti'blvalves 13,

.15and16.. A

, pipe'17 embody a special .feature ihbeing provided with valves made of'thinsheet metal 108 resting .on tubular seats 107 and their ver- 'trcalmovement limited by stops 109.

The water control valves 15are composed 1 of two flanged members 90 and91 with a steel diaphragm 93 clam ed between them by bolts 92. 91 iscappe by a member 101 having a central opening connecting with pipe 35and radial openings 102 leading to valve 99 which is seated on a tubularmember 98. Inside of 98 there .is-a thrust member 97 with guide pins 100and the lower flanged end'of 97 is pressed against dia phragm 93 by aspring 94 of sufiicient strength to hold thediaphragm 93 down and thethrust member 97 away from valve- 99 against any pressure up to, 100pounds er vThe liguor control valves 16 are composed anged members 7 3and 74 with a. steel dia hragm 72 clamped between them of twoby bolts 5.A threaded member'82 screws into 74 to compress spring 81- transmittingpressure to -flanged member -83 centrally guided by a cone attachedlie-diaphragm 72. Below 72 there is a flanged valve mem-' ber 77 pressedagainst the diaphragm by a spring 8 which is only strong enou h to keep77 in contact with 72 as the atter moves up and down. When the pressurein regenerator 11 is less than that due-to sprmg tension 81, the valve77 is forced against seat 80 and'prevents any flow of liquor'from pipe29 throu h' cotton; wool infilterin chamber 86, tn ular member 79, oenings' 5 and 55 into regenerator 11; 'e ad ustment of screwi82determines the absorption pressure in regenerator 11 and the temperaturein-re'fri crating coil'7;

' The equalizing valves 13 are composed oftwo flangedjmembersES and 59with a steel diaphragm 60 clamped between them by bolts '61.. Back ofthe diaphragm 60 there ing. 66 adjusted'to a pressure of 10 is a" M pounin'valve13 and 12-pounds in valve 13; On the opposite side there is aflanged valvemember .68 pressed against diaphragm H 60 by ,a spring 65which is only strong enough to hold 68 in contact with 60 as the v 120'latter moves to and fro. 'With equal pressures on both sides ofdiaphragm60, spring 66will force'valve 68again'stseat 69 and.- prevent any flowof ammonia; gas iron! pipe 1 1 7- through-pipe18 to tne-e i e v orator.r a- Whenregenerator ll istunder-a low pm sure -and absorbing,generator, -pressure diaphragmwwlll overcome spring tension 66 and forcevalve 68 from its seat and admit ammonia gas to the opposite regeneratorvia pipe 18". Whenever the pressure in regenerator 11 is only 12 poundsless than that in generator 1, valve 68 begins to close. In regenerator11*, a difference of less than 10 pounds causes valve 68 -to close. Thetwo-pound difference in tension between springs 66 and 66" is Withouteffect on the operating. functionsof the respective equalizmg valves,but.

the apparatus is not self starting if there is no such difference.

Figure 4. Automatic expansion valve 6 is composed of two flanged membersllland' 112, with a steel diaphragm 110 clamped between them by bolts133. A threaded member113 screws into 112 to compress spring 114transmitting pressure .to flanged member 115 centrally guided by a cone119 attached to diaphragm 110. Below dia-- orifices 130 in screw cap124;, overcomes the tension of spring 114, forces valve 127 01f its seat125, flows down through 120, into refrigerating coil 7. The maximumerator pressure is determined b the adjustment of screw 113 andconditioned by the temperature of the water supply.

The filtering chambers 86 and 86", filled with cotton wool, are providedto filter the weak liquor as it flows into the regenerators tocontinuously remove small particles of any adventitious matter thatmight interfere with proper valve action. 7

Starting with a cold system, properly charged, under a moderate vacuum,we find all the control valves closed. We light burner 2, and presentlythe pressure in generator 1 r1ses until it is 10 pounds per square inchand begins to overcome the spring resistance 66 in valve 13, forcingvalve 68.

' off its seat and-admitting ammonia gas to regenerator 11 through pipes17 and 18.

From this moment on the pressure in-regenerator 11 rises and keeps pacewith the generator pressure up to the maximum for which the expansionvalve 6 is adjusted, but this pressure in regenerator 11 immediatelyreacts against the diaphragm 60 of the valve 13', reinforcing the springtension 66",

holds the valve 68 closed, and-prevents am-' monia gas from flowingthrough pipes 17" genand 18 into regenerator 11" and consequently thelatter retains its vacuum and is ready to receive ammonia gas from therefrigerat-in coil 7. a 1

-With va ves 13 equally tensioned however, there would have been asimultaneous flow of ammonia gas into both'regenerators, kee ing paceWltl the generator ressure, ma ing it impossible to initiate a sorption,and rendering the system. inoperative.

The pressure in the system continues to rise until ,it equals 100 poundsper square inch, opens control valve 15, admits a flow of cold waterfrom pipe-35 via pipe 19 through coil 30, in regenerator 11, crossesover via pipe 36 to intercooler 24 and flows to waste from 37*. Thesystem is thus prepared for absorption in 11* and for cooling hot weakliquor in coil 25", The pressure continues to rise until it equals 200pounds per square inch and forces open the expansion valve 6, initiatesrefrigoration in coil 7, the ammonia gas flowing through check valve 21into regenerator 11.

Presently the rise of pressure in regenerator 11 overcomes the springtension in valve 16 admitting a flow of cold weak li nor to absorb theammonia gas, this liquor aving lost its heat while flowing through coils27 I and 25 Absorption is now 111' progress, its pressure under controlof valve 16, and admitting only enough liquor at any instant tocompletely absorb the ammonia gas.

4 Finally, the regenerator 11 is full of saturated ammonia liquor, afurther rise in pressure throws valve 16 wide open, check valve 21closes, hydrostatic pressure accumulates until it equals the generatorpressure, equalizing valve 13 is closed, control valve 15 is forcedopen, cold water flows via pipe 19 through coil 30 -causing a pressuredrop in 11*, arush of weak liquor through the now 7 wide open valve 16",a rapid absor tion of the contained ammonia gas, and as t e pressurefinally falls below that ofithe adjustment of 16 this valve closes untilammonia gas flowing from refrigerating coil 7 opens 1t again. In themeanti1ne,:as soon as the pressure in regenerator-11 has dropped to. 12pounds less than the pressure in gen-1 erator 1, valve 13 opens andadmits 'am-.

monia gas to the top of the now full regenerator 11'.. In the meantimealso, the rush of-liquor into 11 has brought heating coil 27 into acton, heated thetop' surface of the liquor in 11 to itsboiling point andforced its contents back into the generator via check valve 23 andnozzle 41. Absorption is now proceeding in regener-v ator 11 and asliquor continues 1 to flow through coil 27 it keeps the regenerator 11hot enough to prevent any condensation of ammonia gas therein'until itis ready to reverse and absorb again.-

j faction at .a lower temperature, producing As the weak liquor flowingfrointhe enerator down through the heating coil 2 is usually at atemperature o350 Fahn, and

the boiling point, under generator pressure, of the strong liquor is notusually over 250 7 Fahn, and often much less, the temperature diiferenceand quantity of heat is 'suflieient to boil the upper surface of thesaid liquor, but

The reversals of cycle are effected so quickly that there is only aslight rise of pressure in the refrigerating coil during the period oftransition and therefore no interference with the evaporationof theliquefied ammonia or the continuous production of refrigeration. V r

Should the supply of heat be increased the quantity of ammonia passingthrough expansion valve 6 also increases, pressure in regenerator rises,more liquor isadmitted, the cycles are accelerated, and acorrespondingly greater amount of refrigeration is produced. 1 Thecapacity mayv thus be varied from zeroto the maximum by simplyvaryingthe heat supply and without disturbing any of the other adjustments.

The regenerators are so named.- because they restore to the liquor itsoriginal state of saturation, temperature and pressure,

As many modifications of my inventionwill readily suggest themselves toone skilled in the art, I do not limit or confine my invention to thespecific steps or the exact construction herein shown and described. vIclaim:

.1. The herein described method of con- -tinuous ammonia absorptionrefrigeration of concentration, continuously evaporating ammonia gasfrom said nucleus under. sufficient pressure to subsequently elfectitsliquecontinuous refrigeration by subsequent vaporization of theliquefied. ammonia un-' der a. diminished pressure, extractinghot weakliquor froms'aid nucleus, cooling the extracted liquor causing it toabsorb thesaid, vaporized ammonia, and when said ex- -"-tracted liquorhas become saturated applyingheat thereto to subjectit to pressure andno cause it. to be returnedto the said'nucleus.

" 2, The herein described method of continuous ammonia absorptionrefrigeration whichconsi'sts-in contmuously-applyingheat to a nucleusof. ammon aflhquor m a gradient of concentration, continuously evap'sducing continuous refrigeration by subse-j quent vaporization of theliquefied ammonia under a diminished pressure, extracting hot weakliquor from said nucleus, cooling the extracted liquor causing it toabsorb the said vaporized ammonia, and when said extracted liquorhas'become saturated applying heat thereto derived from the saidnucleus, to

subject the extracted liquor to pressure and cause it to be returnedtothe said nucleus.

3. The herein described method of continuous ammonia absorptionrefrigeration which consists in continuously applying heat to a nucleusof ammonia liquor in a gradient of concentration, continuouslyevaporating ammonia gas from said nucleus under suiiicient pressure tosubsequently efiect its liquefaction at a lower temperature, producingvaporized ammonia, and when said extracted liquor has become saturatedextracting a successive quantity of hot weak liquor from the saidnucleus, transferring heat from the said second quantity to the firstquantity to subject the first quantity to pressure and cause it to bereturned to the said nucleus.

hThe herein described method of continuous ammonia absorptionrefrigeration which consists in continuously applying heat, to a nucleusof ammonia liquor in a gradient of concentration, continuously evaporating ammonia gas from said nucleus under suiiicient pressure tosubsequently effect its liquefaction at a lower temperature, producingcontinuous refrigeration :byfsubse quent' vaporizationof the liquefiedammoma under a. d1m1n1shedpressure,-extracting successive quantities ofhot weak liquor from said nucleus, successively coolmg-sai d extractedquantities, causing. them to 'successively absorb the said vaporizedammonia, and when said extracted quantities have become saturatedcausing them to be heated and their upper surfaces partly vaporized bythejnext successive extracted quantity and thereby generating enoughpressure to l cause their return to the said nucleus;

.5. In fa closed. circulatory ammonia absorption refrigeration system, asingle generator, means 'for continuously applying heat thereto, meansfor maintaining the ammonia liquor inthe generator in a gradient ofstrength "with the weaker liquor at the bottom, 'two. regeneratorsadapted to ,alternately receive I weakv liquor from the generator andtoalternatelv absorb ammonia gas.

received from the refrigerating coil, and means for automatically andsuccessively returning the contents of the regenerators back into thegenerator while heat is being Lapplied thereto.

61 In a closed circulatory ammonia absorption refrigeration system, agenerator,

two regenerators, automatic means r successively ami alternatelydelivering" 0t and 10 cold weak liquor and ammonia gas to theregenerators, means for maintaining generator pressure in one of theregenerators and absorption pressure in the'other, water control andequalizing valves for said regenerators, means for accumulating pressure1n the regenerators upon termination of absorption and therebypositively actuating the water control and equalizing valves governingthe opposite regenerator to efieot a reversal of cycle, specified.

as and for the purpose 20

